Structure of the Earth Flashcards
What shape is the earth?
Spheroid (shaped like a ball, slightly flattened at the top and bottom)
What are the 3 levels that the earth is made up of?
The Crust
The Mantle
The Core
What is the outermost and thinnest layer?
The crust
What is the crust made of
Hard rock
How thick is the crust?
6KM
Where is it thinnest?
Under the ocean
Where is it thickest?
Under tall mountains
What is the approximate temperature?
1200 degrees celsius
What is the Moho?
Boundary between mantle & crust
How thick is the mantle?
2900km
Where do you find the mantle?
Between the crust and the core
What is the top layer of the mantle made?
Hard rock
What are the remaining layers made of?
Semi-molten rock
What do temps of 5000 deg C cause?
Convection current (circular movement of material to move rock in the mantle)
What is the central part of the earth?
The Core
How thick is the core?
3400km
Describe the 2 sections of the core.
Outer Core – molten 2000km
Inner Core – solid 1400km
What is the core probably made of?
Minerals – Iron and Nickel
Temperature of the Core?
5500 degrees C
Other than the temp what is also high in the core?
Pressure
What do the high temps in the Core cause?
Convection current (circular movement of material to move rock in the mantle)
What are the giant slabs or pieces called that make up the earth’s surface?
Plates
How wide can these be?
Thousands of km
What is it called when two tectonic plates bump each other?
Earthquakes
What provides the energy that causes plates to move in the crust?
Convection currents in the rock move through the mantle
What is plate tectonics?
Movement of plates
What is divergent movement?
When plates move away from one another in opposite directions.
Example of Divergent movement?
South American plates and African plates
What happens when 2 plates move aways from one another?
New land is constructed on the crust
What convergent movement?
When the plates move toward each other
Example of convergent movement?
The Eurasian plates and the pacific plate
What is the result of convergent movement?
Land is lost or destroyed as one plate moves under the other back into the mantle
What is transform movement?
When two plates slide past eachother
What is an example of transform movement?
North American Plate at San Andreas Fault
